Sewing-machine



P. A. BOWEN.

SEWING MACHINE.

APPLlCATION FILED MAR. 14, new.

1 3 30, 78 1 Patented Feb. 17, 1920.

2 SHEETS-SHEET I.

P. A. BOWEN.

SEWING MACHINE. APPLICATION FILED MAR. 14. 1919.

1, 0,781. Patented Feb. 17,1920.

2 SHEETSSHEET 2- UNITED STATES PATENT OFFICE.

PHILIP A. BOWEN, OF LYNN, MASSACHUSETTS, ASSIGNOR TO LILLIAN A. LITTLE, OF LYNN, MASSACHUSETTS.

SEWING-MACHINE.

Specification of Letters Patent.

Patented Feb.17, 1920.

Originalapplication filed June 15, 1917, Serial No. 174,912. Divided and this application filed March 14,

- 1919.- Serial No. 282,637.

To all whom it may concern:

Be it known that I, PHILIP A. BOWEN, a citizen of the United States, .residing at Lynn, county of Essex, State ofMassachusetts, have invented an Improvement in Sewing-Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to sewing machines of the type illustrated in my Patents No. 1,250,272, dated December 18, 1917 and No. 1,306,994, dated June 17, 1919, and especially to the take-up mechanism for taking up the under thread and setting the stitch.

The sewing machines illustrated in my said patent and application are lock-stitch sewing machines of that type which embody a horn on which the work is supported and through which the under thread is delivered, a needle situated above the work and operating to penetrate the work and to draw a loop of under thread through the work, a shuttle situated above the work, a looper adapted to take the loop of under thread from the needle and carry the latter around the shuttle, and a take-up mechanism acting to take up the under thread and set each stitch as it is formed.

As stated above, the present invention relates particularly to the take-up mechanism, and the object of the invention is to provide a novel take-u mechanism operating to take up the thread as each stitch is formed thereby to set the stitch, and also operating to draw off from the source of supply as each stitch is formed a sufficient length of thread for the formation of the next stitch.

Inasmuch as the invention relates solely to the take-up mechanism, I have not deemed it necessary to illustrate all the details of a sewing machine, but have simply shown a general view thereof which is sufficient to illustrate how my improvement is applied thereto.

In the drawings, Figure 1 is a side view of a sewing machine such as illustrated in my co-pending application and having my improved take-up thereon; V

Fig. 2 is a plan view of the take-up;

Fig. 3 is a side view thereof looking from the upper side of Fig. 2;

Fig. 4 is a section on the line 44, Fig. 3.

The frame of the sewing machine is indicated at 1 and the horn on which the work is supported is indicated at 4. This horn is provided with a thread passage 2 extending longitudinally therethrough to receive the under thread 11, said thread entering the passage through the trumpet or horn member 32. The frame 1 carries a head 3 in which is mounted a vertically-reciprocating needle bar 37 which derives its reciprocation from a suitable cam supported on the cam shaft 2. This needle bar carries a needle which is arranged to penetrate the work during the downward movement of the needlebar and to draw a loop of under thread from the tip of the horn upwardly through the work during its upward movement. 54 indicates a rotary annular looper member which is constructed to take the loop of under thread which is drawn through the work by the needle and cast said loop about a shuttle which is situated centrally of the looper. After the loop of under thread is thus thrown about the shuttle the take-up mechanism which forms the subject of the present invention operates to pull back- Wardly on the under thread 11 thereby to set the stitch. The take-up mechanism comprises a take-up slide 86 which carries a take-up roll 85 around which the under thread 11 passes so that the movement of this slide to the right Figs. 1 and 2 will draw backwardly on the under thread and thus operate to set the stitch.. The under thread 11 extends from the guiding trumpet 32 through a tension member 83, thence over a guide roll 84, thence around the take-up roll 85 and thence to a thread-locking member 89, and thence through a suitable guide-eye 90 to the source of supply. The

movement in timed relation with the stitchforming mechanism by means of a suitable cam 63 on the cam shaft 2, said cam having a cam groove 100 in which is received a roll 99 carried by the upper end of a lever 97 that is pivoted to the frame at 98. The lower end of the lever 97 is connected by a link 96 to a slotted lever 93 which is pivoted at 94: to a support 6. Thelevcr 93 is con nected by a link 92 to a bracket 91 which is secured to the slide 86. With this construction it will be seen that the movement of the take-up slide 86 to the right in Figs. 1 and 2 or to the left in Fig. 3 will operate to take up slack in the under thread and thus set the stitch. The cam groove 100 is .so designed as to give the take-up member 86 its stitch-setting movement just after the loop of under thread has been cast about the shuttle, and to give said member 86 its movement in the opposite direction to give up thread at the time that the loop is being drawn through the work by the upward movement of the needle.

In order to eifectively set the stitch it is necessary to prevent the take-up roll from drawing thread from the source of supply during its stitch-setting movement, and this is accomplished by the thread-locking device 89, Said locking device is rotatably mounted on the frame 1 and is provided with a groove 7 in which the under thread is received, said thread being wound once or twice about the member 89. This memher is provided with a hub 101 having a groove 102 therein. This groove cooperates with a locking member 103 which has a conical end 104 adapted to frictionally engage the groove 102. This locking member 103 is acted on by a spring 105 which tends to urge the conical end thereof into frictional engagement with the groove 102 thereby locking the member 89 from rotation. The spring is shown as surrounding the locking member 103 and as confined between a pin 106 extending therethrough and a bearing 107 through which the locking member slides.

Means are provided whereby when the take-up slide approaches the end of its stitch-setting movement it will operate to release the lock 103 so that during the final portion of such movement the member 89 is free to rotate. This unlocking of the member 89 occurs just at the time that the stitch is set and the final movement of the slide 86 will, therefore, operate to draw off from the source of supply a length of thread sufficient for the formation of the next stitch. To accomplish this unlocking of the member 89, I have provided the takeup slide 86 with an arm 108 having an aperture through which the locking member 103 extends, and said lockingmember is provided with an adjustable collar 109 which is situated to be engaged by the arm-108 just before the take-up slide 86 reaches the limit of the stitch-setting movement which is toward the right in Fig. 2. Then the arm 108 engages the collar 109, then further movement of the slide 86 will' move the locking member 103 to the right against the action of the spring 105, thus withdrawing the conical end 101 from engagement with the groove 102. This releases the member 89 so that it will be free to rotate to allow thread to be drawn off from the source of supply.

My improved device, therefore, not only takes up the under thread to set each stitch, but also at each movement draws ofi'from the source of supply an additional length of thread suliicient to form the next stitch.

The cam groove 100 is so constructed that the take-up member will be held in its retracted position, thus holding the lock 103 inoperative, while the needle is making its penetrating thrust. As the needle is retracted to draw a loop of under thread through the work the slide 86 is moved forwardly, thus giving up the thread which is thus drawn through the work.

This application is a division of my application Ser. No. 174,912, filed June 15, 1917, which matured into the above-mom tioned latent No. 1,306,994.

I claim:

1. A look stitch sewing machine having in combination means for interlocking upper and under threads and a take-up mechanism for setting the stitch, said take-up mechanism comprising a reciprocating take-up member having provision to engage the thread, a member rotatable about a fixed axis and about which is wound the portion of the thread extending from the take-up member to the thread supply, and a springpressed locking member adapted to engage said rotatable member thereby frictionally holding the same from rotation, said take- 110 up member having means to engage the spring-pressed locking member just as it completes its stitch-setting movement thereby to withdraw the locking member from engagement with the rotatable member.

2. A sewing machine having in combination means for interlocking upper and under threads, a reciprocating take-up memher having provision to engage one of the threads, a member rotatable about a fixed 12 axis and about which is wound the portion of the thread extending from the take-up member to the thread supply, automaticallyoperative means to lock the rotatable member from rotative movement, and lock-re- 125 leasing means operated by the take-up memher as it is completing its stitch-setting movement.

3. A sewing machine having in combina- 4 tion means for interlocking upper and un- 130 der threads, a reciprocating take-up member having provision to engage one of the threads, a member rotatable about a fixed axis and about Which is Wound the portion of the thread extending from the take-up member .to the thread supply, a springpressed brake device frictionally engaging said rotatable member, and means to release the frictional engagement of said brake member With the rotatable member as the 10 take-up member is completing its stitchsetting movement.

In testimony whereof I have signed my name to this specification.

PHILIP A. BOWEN. 

